In this image-anatomical study we used magnetic resonance imaging to analyze the numbers and diameters of the basilic vein（BA）, median basilic vein（MBA）, median cubital vein（MC）, median cephalic vein（MCE）, and cephalic vein（CE）, which are utilized for drawing blood and intravenous injections in the cubital fossa. In addition, correlations between cutaneous vein diameters and participant characteristics were estimated.
In an analysis of the number of cutaneous veins in 105 people（63 men and 42 women）, the BA was most frequent, and the MC was the least frequent. The mean diameter of the MBA, MC, and MCE was significantly larger than those of the BA and CE in men and women. The MC had the largest diameter in men and women. There was no significant difference in diameter when cutaneous veins were divided into two areas（BA, MBA）and（MCE, CE）. Because the median nerve and brachial artery and vein run deep in the ulnar area of the cubital fossa, venipuncture should first be administered in the MBA, MC, and MCE, because of their large diameters.
The diameters of cutaneous veins were correlated with body weight. The correlation of body weight with cutaneous vein diameters likely explains the correlation between body mass index and vein diameters.